The solution to this is just nonviolently retire the character or just not use them.
Like I recently read the Venom/Carnage book that introduced Toxin and his original host Patrick. I don't have a problem with Pat no longer being Toxin, my issue is the horrific end he got. Him and his wife and child brutally murdered by Blackheart offscreen, why did he have to be given such a nasty ending?
I get retiring a character, but you don't have to be so excessively mean-spirited about it.